Effect of stem bromelain on the browning of apple juice

Abstract

The effectiveness of pineapple stem protease (brornelain) in enzymatic browning inhibition was evaluated on apple juice and compared with that of L-cysteine and ascorbic acid at 25±1°C. The relative effectiveness of these anti-browning agents was determined interms of color (L*) and enzymatic activity measurements with respect to time. L-cysteine at 0.7 and 1.0 mM concentrations gave the best results though the latter is associated with undesirable odor and bleaching effect. Ascorbic acid seemed to be only effective within the first 5 h after which its effectiveness dropped sharply. Stem bromelain, as compared to both L-cysteine and ascorbic acid, was found weakest in enzymatic browning inhibition hence considered ineffective. © 2009 Academic Journals Inc.